3-(Trimethyl­sil­yl)prop-2-ynyl p-toluene­sulfonate

In the title compound, C₁₃H₁₈O₃SSi, the SO₃ group displays a partial rotational (ca 50°) disorder about the C-S bond, with relative proportions 0.7744 (13):0.2256 (13). This disorder also forces the propynyl CH₂ group to be disordered.

Key indicators

• Single-crystal X-ray study
• T = 90 K, P = 0.0 kPa
• Mean [sigma](C-C) = 0.003 Å
• Disorder in main residue
• R factor = 0.045
• wR factor = 0.108
• Data-to-parameter ratio = 26.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT230_ALERT_2_B Hirshfeld Test Diff for    S1     --  O1A     ..        8.3 su
PLAT230_ALERT_2_B Hirshfeld Test Diff for    S1     --  O3A     ..       14.8 su
PLAT230_ALERT_2_B Hirshfeld Test Diff for    Si1    --  C10     ..        7.4 su

Alert level C
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          2
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600         30

Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          3
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT301_ALERT_3_G Note: Main Residue  Disorder ...................         17 Perc.
PLAT432_ALERT_2_G Short Inter X...Y Contact  C12    ..  O2A     ..       2.93 Ang.
PLAT720_ALERT_4_G Number of Unusual/Non-Standard Labels ..........          2
PLAT811_ALERT_5_G No ADDSYM Analysis: Too Many Excluded Atoms ....          !
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

   0 ALERT level A = Most likely a serious problem - resolve or explain
   3 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   7 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   5 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   2 ALERT type 5 Informative message, check

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S1. Comment

The title compound was prepared as an intermediate in the synthesis of 3-methyl substituted benz[f]indole derivatives (Morales, 1995). It has been described as a colorless liquid at room temperature (Tanabe et al., 1995; Westmijze & Vermeer, 1979). Our initial synthesis, by treating 3-trimethylsilylpropargyl alcohol with freshly powdered KOH and freshly recrystallized p-toluenesulfonyl chloride in ether at -50°C, also yielded the desired sulfonate as a liquid. However, after several recrystallizations from hexanes, suitable single crystals were obtained as colorless needles with melting point 43–44°C.

3-Trimethylsilyl-2-propynyl p-toluenesulfonate contains a p-toluenesulfonate group with the S(O)₂OCH₂ group partially (22.56 (13)%) disordered by rotation of ca 50° about the C–S bond. The disorder was modelled with constrained partial occupancy of two O₃ and two H₂ sites. The disordered O–C bond distances were restrained to be approximately equal (to within σ = 0.002 Å) to compensate for disorder of the C atom itself. The two partial S–O bonds average 1.574 (2) Å, and the four partial S═O bonds average 1.435 (1) Å.

Related literature

For information on the title compound, see: Westmijze & Vermeer (1979); Tanabe et al. (1995); Morales (1995).

S2. Experimental

The title compound was prepared according to the procedure of Westmijze & Vermeer (1979): Commercially available 3-trimethylsilylpropargyl alcohol (5.13 g, 40.0 mmol) and freshly purified tosyl chloride (9.53 g, 50.0 mmol) were mixed in anhydrous diethyl ether under an Ar atmosphere. The mixture was cooled to -50 °C, and freshly powdered KOH (15.0 g, 268 mmol) was added at once under vigorous stirring. The temperature of the resulting thick mixture was slowly raised to 0 °C, and the mixture was stirred at this temperature for 30 min. This mixture was poured onto water (200 ml), extracted with ethyl ether (3 τimes 50 ml), washed with water (100 ml), and concentrated under reduced pressure to give a light brown oil. Repeated crystallization from hexanes afforded colorless needles (7.93 g, 70.3% yield).

S3. Refinement

The site occupation factor was constrained to be x for O1, O2, O3, H8A, H8B, and 1 - x for O1A, O2A, O3A, H8A', H8B'. Atomic displacement parameters were constrained to be equal for the following disordered atom pairs: O1 and O1A, O2 and O2A, O3 and O3A, and interatomic distances C8—O1 and C8—O1A were restrained to be equal to within σ = 0.002.

All H atoms were placed in calculated positions, guided by difference maps, with C—H bond distances 0.95 (aromatic-H), 0.98 (methyl-H), and 0.99 (alkyl-H) Å, and displacement parameters U_iso=1.2U_eq (aromatic and alkyl C) and 1.5U_eq (methyl-C), and thereafter refined as riding.

Computing details

Data collection: COLLECT (Nonius, 2000); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

Fig. 1. View of (I) showing 50% probability displacement ellipsoids. The two disordered components of the sulfonate group are shown, while only the major component of the attached disordered methylene group is drawn.

3-(Trimethylsilyl)prop-2-ynyl p-toluenesulfonate

Crystal data

C13H18O3SSi	F(000) = 600
Mr = 282.42	Dx = 1.245 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 4768 reflections
a = 10.6857 (4) Å	θ = 2.6–31.0°
b = 12.9413 (5) Å	µ = 0.29 mm^−1
c = 11.8793 (4) Å	T = 90 K
β = 113.471 (2)°	Needle, colorless
V = 1506.83 (10) Å^3	0.33 × 0.18 × 0.17 mm
Z = 4

Data collection

Nonius KappaCCD diffractometer	4721 independent reflections
Radiation source: fine-focus sealed tube	3257 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.041
Detector resolution: 9 pixels mm^-1	θmax = 30.9°, θmin = 2.6°
ω and ϕ scans	h = −15→15
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997)	k = −18→18
Tmin = 0.910, Tmax = 0.952	l = −17→16
9135 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.108	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0404P)^2 + 0.7293P] where P = (Fo^2 + 2Fc^2)/3
4721 reflections	(Δ/σ)max = 0.001
177 parameters	Δρmax = 0.76 e Å^−3
1 restraint	Δρmin = −0.54 e Å^−3
3 constraints

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
S1	1.00481 (4)	0.33704 (3)	0.46346 (4)	0.01708 (10)
Si1	0.49810 (5)	0.23584 (4)	0.04270 (4)	0.02127 (12)
O1	0.87983 (15)	0.41268 (11)	0.42804 (13)	0.0207 (3)	0.7744 (13)
O2	1.08780 (16)	0.36473 (12)	0.39833 (15)	0.0237 (3)	0.7744 (13)
O3	1.06468 (17)	0.33877 (12)	0.59590 (14)	0.0250 (3)	0.7744 (13)
O1A	0.9453 (3)	0.4058 (4)	0.3433 (4)	0.0207 (3)	0.2256 (13)
O2A	1.1404 (6)	0.3363 (4)	0.4827 (5)	0.0237 (3)	0.2256 (13)
O3A	0.9569 (6)	0.3761 (4)	0.5540 (5)	0.0250 (3)	0.2256 (13)
C1	0.93291 (17)	0.21448 (12)	0.41521 (15)	0.0178 (3)
C2	0.86434 (19)	0.16667 (14)	0.47865 (16)	0.0240 (4)
H2	0.8564	0.1997	0.5469	0.029*
C3	0.8077 (2)	0.06981 (14)	0.44071 (17)	0.0282 (4)
H3	0.7606	0.0364	0.4836	0.034*
C4	0.81874 (18)	0.02064 (13)	0.34052 (16)	0.0257 (4)
C5	0.88776 (18)	0.07073 (13)	0.27880 (16)	0.0246 (4)
H5	0.8955	0.038	0.2102	0.03*
C6	0.94568 (17)	0.16762 (13)	0.31531 (15)	0.0212 (3)
H6	0.993	0.2011	0.2728	0.025*
C7	0.7575 (2)	−0.08509 (15)	0.3004 (2)	0.0377 (5)
H7A	0.7553	−0.1005	0.2188	0.057*
H7C	0.6645	−0.0864	0.2972	0.057*
H7B	0.8131	−0.137	0.3591	0.057*
C8	0.81275 (19)	0.45147 (14)	0.30416 (16)	0.0272 (4)
H8A	0.8829	0.4663	0.2715	0.033*	0.7744 (13)
H8B	0.7671	0.5175	0.3066	0.033*	0.7744 (13)
H8A'	0.8112	0.518	0.2626	0.033*	0.2256 (13)
H8B'	0.7906	0.4652	0.3762	0.033*	0.2256 (13)
C9	0.71152 (19)	0.38092 (14)	0.21960 (16)	0.0237 (4)
C10	0.62740 (19)	0.32454 (14)	0.14905 (16)	0.0247 (4)
C11	0.58308 (19)	0.15508 (16)	−0.03569 (18)	0.0314 (4)
H11A	0.6075	0.1983	−0.0916	0.047*
H11B	0.5207	0.1003	−0.0824	0.047*
H11C	0.6658	0.1241	0.0257	0.047*
C12	0.4334 (2)	0.15281 (15)	0.13563 (19)	0.0333 (4)
H12A	0.51	0.1164	0.1983	0.05*
H12B	0.3686	0.1023	0.0821	0.05*
H12C	0.3876	0.1959	0.1755	0.05*
C13	0.36123 (19)	0.31849 (14)	−0.06735 (17)	0.0270 (4)
H13A	0.3137	0.355	−0.0237	0.041*
H13B	0.2962	0.2751	−0.1317	0.041*
H13C	0.4018	0.3688	−0.1045	0.041*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.01972 (19)	0.01537 (18)	0.01643 (19)	−0.00309 (16)	0.00751 (15)	−0.00186 (15)
Si1	0.0256 (2)	0.0199 (2)	0.0190 (2)	−0.0004 (2)	0.00962 (19)	−0.00338 (19)
O1	0.0220 (7)	0.0174 (7)	0.0228 (8)	−0.0009 (6)	0.0091 (6)	−0.0038 (6)
O2	0.0242 (8)	0.0217 (8)	0.0295 (8)	−0.0020 (6)	0.0152 (7)	0.0019 (6)
O3	0.0322 (8)	0.0222 (8)	0.0168 (7)	−0.0078 (7)	0.0058 (6)	−0.0022 (6)
O1A	0.0220 (7)	0.0174 (7)	0.0228 (8)	−0.0009 (6)	0.0091 (6)	−0.0038 (6)
O2A	0.0242 (8)	0.0217 (8)	0.0295 (8)	−0.0020 (6)	0.0152 (7)	0.0019 (6)
O3A	0.0322 (8)	0.0222 (8)	0.0168 (7)	−0.0078 (7)	0.0058 (6)	−0.0022 (6)
C1	0.0199 (8)	0.0136 (7)	0.0176 (8)	−0.0008 (6)	0.0050 (6)	−0.0020 (6)
C2	0.0311 (9)	0.0206 (8)	0.0227 (8)	−0.0059 (7)	0.0134 (7)	−0.0051 (7)
C3	0.0346 (10)	0.0207 (9)	0.0307 (10)	−0.0075 (8)	0.0144 (8)	−0.0006 (7)
C4	0.0253 (9)	0.0159 (8)	0.0268 (9)	0.0007 (7)	0.0006 (7)	−0.0028 (7)
C5	0.0294 (9)	0.0199 (8)	0.0200 (8)	0.0056 (7)	0.0049 (7)	−0.0058 (7)
C6	0.0246 (8)	0.0203 (8)	0.0184 (8)	0.0035 (7)	0.0083 (7)	−0.0008 (7)
C7	0.0426 (12)	0.0185 (9)	0.0417 (12)	−0.0053 (8)	0.0059 (10)	−0.0078 (8)
C8	0.0314 (9)	0.0178 (8)	0.0256 (9)	0.0002 (7)	0.0043 (8)	0.0018 (7)
C9	0.0291 (9)	0.0212 (8)	0.0224 (9)	0.0032 (7)	0.0120 (7)	0.0018 (7)
C10	0.0317 (10)	0.0241 (9)	0.0199 (8)	0.0008 (7)	0.0120 (7)	−0.0004 (7)
C11	0.0257 (9)	0.0394 (11)	0.0267 (9)	0.0020 (8)	0.0079 (8)	−0.0119 (8)
C12	0.0434 (12)	0.0255 (10)	0.0342 (11)	−0.0013 (9)	0.0191 (9)	0.0022 (8)
C13	0.0299 (9)	0.0251 (9)	0.0250 (9)	0.0012 (7)	0.0100 (8)	−0.0014 (7)

Geometric parameters (Å, º)

S1—O2A	1.374 (5)	C5—C6	1.389 (2)
S1—O2	1.4352 (15)	C5—H5	0.95
S1—O3	1.4434 (15)	C6—H6	0.95
S1—O3A	1.454 (6)	C7—H7A	0.98
S1—O1	1.5720 (15)	C7—H7C	0.98
S1—O1A	1.584 (5)	C7—H7B	0.98
S1—C1	1.7561 (16)	C8—C9	1.465 (2)
Si1—C10	1.8526 (19)	C8—H8A	0.99
Si1—C11	1.8594 (19)	C8—H8B	0.99
Si1—C12	1.8600 (19)	C8—H8A'	0.99
Si1—C13	1.8625 (19)	C8—H8B'	0.99
O1—C8	1.446 (2)	C9—C10	1.201 (3)
O1A—C8	1.430 (3)	C11—H11A	0.98
C1—C6	1.387 (2)	C11—H11B	0.98
C1—C2	1.388 (2)	C11—H11C	0.98
C2—C3	1.387 (2)	C12—H12A	0.98
C2—H2	0.95	C12—H12B	0.98
C3—C4	1.396 (3)	C12—H12C	0.98
C3—H3	0.95	C13—H13A	0.98
C4—C5	1.390 (3)	C13—H13B	0.98
C4—C7	1.510 (2)	C13—H13C	0.98
O2—S1—O3	118.88 (10)	C4—C7—H7A	109.5
O2A—S1—O3A	122.5 (3)	C4—C7—H7C	109.5
O2—S1—O1	109.98 (9)	H7A—C7—H7C	109.5
O3—S1—O1	104.04 (9)	C4—C7—H7B	109.5
O2A—S1—O1A	99.9 (3)	H7A—C7—H7B	109.5
O3A—S1—O1A	109.7 (3)	H7C—C7—H7B	109.5
O2A—S1—C1	110.1 (2)	O1A—C8—C9	109.3 (2)
O2—S1—C1	109.48 (9)	O1—C8—C9	114.37 (15)
O3—S1—C1	108.43 (8)	O1—C8—H8A	108.7
O3A—S1—C1	108.6 (2)	C9—C8—H8A	108.7
O1—S1—C1	105.10 (8)	O1—C8—H8B	108.7
O1A—S1—C1	104.31 (19)	C9—C8—H8B	108.7
C10—Si1—C11	108.03 (9)	H8A—C8—H8B	107.6
C10—Si1—C12	107.80 (9)	O1A—C8—H8A'	109.8
C11—Si1—C12	110.10 (10)	C9—C8—H8A'	109.8
C10—Si1—C13	106.66 (8)	O1A—C8—H8B'	109.8
C11—Si1—C13	112.01 (9)	C9—C8—H8B'	109.8
C12—Si1—C13	112.01 (9)	H8A'—C8—H8B'	108.3
C8—O1—S1	120.83 (12)	C10—C9—C8	178.9 (2)
C8—O1A—S1	121.0 (3)	C9—C10—Si1	178.90 (17)
C6—C1—C2	121.51 (15)	Si1—C11—H11A	109.5
C6—C1—S1	119.66 (13)	Si1—C11—H11B	109.5
C2—C1—S1	118.83 (12)	H11A—C11—H11B	109.5
C3—C2—C1	118.87 (16)	Si1—C11—H11C	109.5
C3—C2—H2	120.6	H11A—C11—H11C	109.5
C1—C2—H2	120.6	H11B—C11—H11C	109.5
C2—C3—C4	121.00 (17)	Si1—C12—H12A	109.5
C2—C3—H3	119.5	Si1—C12—H12B	109.5
C4—C3—H3	119.5	H12A—C12—H12B	109.5
C5—C4—C3	118.69 (16)	Si1—C12—H12C	109.5
C5—C4—C7	120.67 (17)	H12A—C12—H12C	109.5
C3—C4—C7	120.64 (18)	H12B—C12—H12C	109.5
C6—C5—C4	121.35 (16)	Si1—C13—H13A	109.5
C6—C5—H5	119.3	Si1—C13—H13B	109.5
C4—C5—H5	119.3	H13A—C13—H13B	109.5
C1—C6—C5	118.58 (16)	Si1—C13—H13C	109.5
C1—C6—H6	120.7	H13A—C13—H13C	109.5
C5—C6—H6	120.7	H13B—C13—H13C	109.5
O2—S1—O1—C8	36.57 (16)	O3—S1—C1—C2	40.01 (17)
O3—S1—O1—C8	164.93 (14)	O3A—S1—C1—C2	−10.1 (3)
C1—S1—O1—C8	−81.18 (15)	O1—S1—C1—C2	−70.77 (15)
O2A—S1—O1A—C8	−163.6 (4)	O1A—S1—C1—C2	−127.00 (18)
O3A—S1—O1A—C8	−33.6 (5)	C6—C1—C2—C3	0.0 (3)
C1—S1—O1A—C8	82.5 (4)	S1—C1—C2—C3	−179.91 (14)
O2A—S1—C1—C6	−53.4 (3)	C1—C2—C3—C4	−0.1 (3)
O2—S1—C1—C6	−8.82 (17)	C2—C3—C4—C5	−0.1 (3)
O3—S1—C1—C6	−139.95 (14)	C2—C3—C4—C7	179.61 (18)
O3A—S1—C1—C6	170.0 (3)	C3—C4—C5—C6	0.3 (3)
O1—S1—C1—C6	109.28 (14)	C7—C4—C5—C6	−179.42 (17)
O1A—S1—C1—C6	53.05 (19)	C2—C1—C6—C5	0.1 (3)
O2A—S1—C1—C2	126.6 (3)	S1—C1—C6—C5	−179.91 (13)
O2—S1—C1—C2	171.14 (14)	C4—C5—C6—C1	−0.3 (3)